Defending Earth: the Threat from Asteroid and Comet Impact
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Defending Earth: The Threat from Asteroid and Comet Impact Version A | 05 September 2009 Mr. A.C. Charania President, Commercial Division | SpaceWorks Engineering, Inc. (SEI) | [email protected] | 1+770.379.8006 Acknowledgments: Multiple slides from Dr. Clark Chapman, Southwest Research Institute Boulder, Colorado, USA, URL: www.boulder.swri.edu/~cchapman 1 Copyright 2009, SpaceWorks Engineering, Inc. (SEI) | www.sei.aero Source: NASA/JPL/Infrared Telescope Facility 2009 Jupiter Impact Event: 19 July 2009 (1 km Sized Object) 2 Copyright 2009, SpaceWorks Engineering, Inc. (SEI) | www.sei.aero Source: JPL / NASA Spitzer Space Telescope 95 Light Years Away (Star HD 172555): Moon-Sized Object Impacts Mercury-Sized Object at 10 km/s (5.8+/-0.6 AU Orbit) 3 Copyright 2009, SpaceWorks Engineering, Inc. (SEI) | www.sei.aero SPACEWORKS 4 Copyright 2009, SpaceWorks Engineering, Inc. (SEI) | www.sei.aero KEY CUSTOMERS AND PRODUCTS 5 Copyright 2009, SpaceWorks Engineering, Inc. (SEI) | www.sei.aero DOMAIN OF EXPERTISE: ADVANCED CONCEPTS 6 Copyright 2009, SpaceWorks Engineering, Inc. (SEI) | www.sei.aero INTRODUCTION 7 Copyright 2009, SpaceWorks Engineering, Inc. (SEI) | www.sei.aero − Asteroid - A relatively small, inactive, rocky body orbiting the Sun − Comet - A relatively small, at times active, object whose ices can vaporize in sunlight forming an atmosphere (coma) of dust and gas and, sometimes, a tail of dust and/or gas − Meteoroid - A small particle from a comet or asteroid orbiting the Sun − Meteor - The light phenomena which results when a meteoroid enters the Earth's atmosphere and vaporizes; a shooting star − Meteorite -A meteoroid that survives its passage through the Earth's atmosphere and lands upon the Earth's surface − NEO - Near Earth Object (within 0.3 AU) − PHOs - Potentially Hazardous Objects (within 0.025 AU) COMMON DEFINITIONS 8 Copyright 2009, SpaceWorks Engineering, Inc. (SEI) | www.sei.aero − NEOs have affected our environment and will continue to do so − Early sources of water, organic molecules on Earth − Bombardment “blizzard”: the Late Heavy Bombardment, ~3.9 Ga, which frustrated the origin of life − External cause for “punctuated equilibrium” evolution, mass extinctions, rise of new species − Rare, modern threat to humanity − Future source of raw materials, spacefaring tourist destinations Julian Baum Don Dixon Chesley Bonestell Sources: - "How Dangerous are Near-Earth Asteroids?," Clark R. Chapman, Southwest Research Institute Boulder, Colorado, USA, 2007 Space Weather Workshop Reception, After-Dinner Talk, UCAR Center Green Campus, Bldg. 1, 25 April 2007. THE IMPACT OF NEOS ON EXISTENCE 9 Copyright 2009, SpaceWorks Engineering, Inc. (SEI) | www.sei.aero Comets: − Represent remnants from outer solar system formation process − Dust and gas are lost with each solar passage; evolve into fragile structures that can disintegrate or collide with the sun or planets − May have delivered water and organics to early Earth − Near-Earth comets: 100 times less frequent than near-Earth asteroids but comets may dominate large end of NEO population Asteroids: − Represent remnants from inner solar system formation process − May have contributed water and organics to early Earth − Extremely diverse population (differing strengths, minerals & metals) − Some near-Earth asteroids are more accessible than the moon and could be mined for minerals and metals. − Represent remnants from inner solar system formation process − May have contributed water and organics to early Earth − Extremely diverse population (differing strengths, minerals & metals) − Some near-Earth asteroids are more accessible than the moon and could be mined for minerals and metals. COMETS AND ASTEROIDS 10 Copyright 2009, SpaceWorks Engineering, Inc. (SEI) | www.sei.aero Comets (weak and very black icy dust balls) − Weak collection of talcum-powder sized silicate dust − About 30% ices (mostly water) just below surface dust − Fairly recent resurfacing and few impact craters − Resurfacing could be due to dusty vaporization jets − Some evidence that comet Tempel 1 does not have a uniform composition (i.e., more CO2in south) Asteroids − Run the gamut from wimpy ex-comet fluff balls to slabs of iron − Most are shattered fragments of larger asteroids − Rubble rock piles (like Itokawa) − Shattered (but coherent) rock (like Eros) − Solid rock − Solid slabs of iron (like Meteor crater object) DIVERSE STRUCTURE 11 Copyright 2009, SpaceWorks Engineering, Inc. (SEI) | www.sei.aero Object Size Comparisons Asteroid Itokawa, ISS, and CEV Orion NEAR EARTH OBJECT (NEO) EXAMPLES 12 Copyright 2009, SpaceWorks Engineering, Inc. (SEI) | www.sei.aero At 59m, 6mm/pixel Global Shape of Itokawa: Sea Otter in Space? 13 Copyright 2009, SpaceWorks Engineering, Inc. (SEI) | www.sei.aero − NEAR − Launch (February 17, 1996), Asteroid Mathilde Flyby (June 27, 1997), Asteroid Eros Initial Flyby (December 23, 1998), Asteroid Eros Rendezvous (February 14, 2000) − The NEAR mission flew within 1200 km of asteroid Mathilde and spent nearly one year in orbit about asteroid Eros in 2001-2001. − DEEP SPACE 1 − Launch (October 25, 1998), Asteroid 9969 Braille Flyby (July 28, 1999), Comet Borrelly Flyby (September 22, 2001) − The primary Deep Space 1 mission objectives are test space technologies. The spacecraft flew within 2000 km of Comet Borrelly on September 22, 2001. − STARDUST − Launch (February 6, 1999), Comet Wild-2 Flyby (January 2, 2004), Earth Sample Return (January 15, 2006) − The STARDUST spacecraft will image the nucleus of Comet Wild-2, collect dust from both the comet's coma and from interplanetary space and bring these dust samples back to Earth for study. − MUSES-C/HAYABUSA − Launch (December 2002), Asteroid 25143 Itokawa Rendezvous (September 2005), Earth Sample Return (2010) − A cooperative mission between Japan and the U.S., the MUSES-C spacecraft will rendezvous with a near-Earth asteroid and return asteroid surface samples to Earth for analysis. − ROSETTA − Launch (March 2, 2004), Comet Churyumov-Gerasimenko Rendezvous (May 2014) − After three Earth gravity assists and a Mars gravity assit, the Rosetta spacecraft will rendezvous with, land upon, the surface of a comet in an effort to study its composition and structure. − DEEP IMPACT − Launch (December 30, 2004), Comet Tempel 1 Impact/Flyby (July 4, 2005) − Deep Impact mission will impact the surface of comet Tempel 1 thus creating a fresh crater larger than the size of football field and deeper than a seven-story building. The spacecraft will study the crater formation process and examine the subsurface structure of one of the solar system's most primitive objects, a remnant from the outer solar system formation process. − DAWN − Launch (May 2006), Asteroid Vesta Rendezvous (July 2010), Asteroid Ceres Rendezvous (August 2014) − The Dawn mission will orbit two asteroids on a single voyage. Ceres and Vesta evolved under radically different circumstances in different parts of the solar system more than 4.6 billion years ago. By observing both protoplanets with the same set of instruments, Dawn will provide new insight into the formation and evolution of our solar system. Sample of Recent Comet And Asteroid Missions 14 Copyright 2009, SpaceWorks Engineering, Inc. (SEI) | www.sei.aero QUANTIFYING THE THREAT 15 Copyright 2009, SpaceWorks Engineering, Inc. (SEI) | www.sei.aero 1800 1900 1950 1990 1999 2009 September Source: http://www.arm.ac.uk/neos/ EVOLVING NEAR EARTH OBJECT MAPS OF THE INNER SOLAR SYSTEM 16 Copyright 2009, SpaceWorks Engineering, Inc. (SEI) | www.sei.aero 2009 (05 Sept) Within 0.3 AU The image below is an up to date map showing the local space around the Earth in pseudo 3D. All the objects currently within 0.3 AU (45 Million kilometres) of the Earth are shown with the Earth at the centre. To represent the 3D nature of the positions every asteroid marked has its position projected onto the plane of the ecliptic (essentially the plane which the Earth's orbit lies in). So the asteroid sits at the top (or bottom) of the 'flagpole' and the base of the pole shows where they would appear to be on the larger map of near Earth objects. In addition, the motion over the next 24 hours is represented by lines at the top of the poles. The Viewpoint is about 35 degrees away from the vertical and the scale is about 10 times more detailed than in the complete map of asteroids. The asteroids are colour coded such that all yellow objects have perihelia inside the Earth's orbit while all the green objects have perihelion distances outside the Earth's orbit. Everything which appears on this map can be considered to be an Earth approaching asteroid. The red oval surrounding the earth represents 3.84 million kilometres (projected onto the plane). This is a distance equal to 10 Lunar distances. Any object currently inside this distance will be highlighted in red. Source: http://szyzyg.arm.ac.uk/~spm/local_map.html RELATIVE POSITIONS OF ASTEROIDS NEAR EARTH 17 Copyright 2009, SpaceWorks Engineering, Inc. (SEI) | www.sei.aero Source: http://neo.jpl.nasa.gov/stats/ NUMBER OF NEAR-EARTH ASTEROIDS (NEAS) 18 Copyright 2009, SpaceWorks Engineering, Inc. (SEI) | www.sei.aero Source: http://neo.jpl.nasa.gov/stats/ NUMBER OF NEAR-EARTH ASTEROIDS (NEAS) DISCOVERED 19 Copyright 2009, SpaceWorks Engineering, Inc. (SEI) | www.sei.aero Incremental numbers: 0.5 mag. Intervals centered on listed mag. and size. Data courtesy A. Harris (June 2007) H Diam. (km) Known Now SG1 (goal) SG2 (goal) No. % of Tot. No. % of Tot. No. % of Tot. 17.75 1.0 234 59 280 83 333 98 22.02 0.14 162 3.5 450 9 4000 83 24.26 0.05 147 0.09 1200 0.6 80000 40 25.36 0.03 85 0.01 640 0.08 2 M 20 27.75 0.01 17 1e(-6) 200 1e(-5) 400000 2 29.26 0.005 6 3e(-8) 30 3e(-7) 200000 0.2 − The discovery rate for 10 m NEAs may go up 2000 times! − By the end of SG2, we will know nearly half of Tunguska-class NEAs.